Culture

Popularity distance between a restaurant's location and a person's hometown biases ratings

CATONSVILLE, MD, February 6, 2020 - Product reviews and ratings have a strong impact on consumer consideration. In restaurant reviews, new research upcoming in the INFORMS journal Information Systems Research shows that location bias, based on the popularity difference between the reviewer's hometown and the distance to their destination, can affect a reviewers online rating by as much as 11%.

The study, "Your Hometown Matters: Popularity-Difference Bias in Online Reputation Platforms," conducted by Marios Kokkodis of Boston College and Theodoros Lappas of Stevens Institute of Technology, found when reviewers travel to a less popular location than their hometown, they review with a negative tendency. When reviewers travel to a more popular location than their hometown they review with a positive tendency.

In this study, Kokkodis and Lappas analyzed more than 760,000 restaurant reviews from nearly 1,500 cities in the continental U.S. In that dataset alone they said bias affected 98% of the restaurants.

"This effect on ratings alters the probability that an average customer will consider a restaurant by up to 16%. This is because the bias can distort online reputations, leading to misrepresented businesses and misinformed users," said Kokkodis, a professor in the Carroll School of Management at Boston College.

Awareness of the popularity-difference bias allows managers to improve the design of their ranking systems. The study shows such improvements can lead to up to 12% higher reviewer satisfaction and up to 24% more diversified top-restaurant recommendations.

Credit: 
Institute for Operations Research and the Management Sciences

UNH researchers find synchronization of memory cells critical for learning and forming memories

image: On the left is an enlarged image showing many hippocampal neurons, most of which are silent and only a few are active. On the right are close ups of three highly active neurons, or memory cells, which become synchronized after memory formation (images modified from Zhou et al., 2020 FASEB Journal).

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UNH

DURHAM, N.H. - The phrase "Pavlov's dogs" has long evoked images of bells, food and salivating dogs. Even though this tried-and-true model of repetitive patterns mimics a variety of learning processes, what happens on a cellular level in the brain isn't clear. Researchers at the University of New Hampshire took a closer look at the hippocampus, the part of the brain critical for long-term memory formation, and found that the neurons involved in so-called Pavlovian learning shift their behavior during the process and become more synchronized when a memory is being formed - a finding that helps better understand memory mechanisms and provides clues for the development of future therapies for memory-related diseases like dementia, autism and post-traumatic stress disorder (PTSD).

"There are tens of millions of neurons in the hippocampus but only a small fraction of them are involved in this learning process" said Xuanmao (Mao) Chen, assistant professor of neurobiology. "Before engaging in Pavlovian conditioning, these neurons are highly active, almost chaotic, without much coordination with each other, but during memory formation they change their pattern from random to synchronized, likely forging new connecting circuits in the brain to bridge two unrelated events.

In the study, recently published in The FASEB Journal, researchers looked at Pavlovian learning patterns, or respondent conditioning, in mice. In the beginning, before any repetitive learning exercises, the mice did not know what to expect and using special imaging with an endomicroscope the researchers saw that the neural activity was disorderly. But after repeating different tasks associated with a conditional stimulus, like a tone or bell, the mice began to recognize the pattern and the highly active neurons became more synchronized. The researchers hypothesize that without forming synchronization, animals cannot form or retrieve this type of memory.

In the 1890's, Russian psychologist, Ivan Pavlov discovered classical conditioning through repetitive patterns of bell ringing which signaled to his dogs that food was on its way and stimulated salivation. This same learned behavior is important for episodic knowledge which is the basis for such things as learning vocabulary, textbook knowledge, and memorizing account passwords. Abnormal learning processing and memory formation are associated with a number of diseases like dementia, autism, and PTSD. People who struggle with these cognitive dysfunction-related disorders may have trouble retaining memories or can even form too strong a memory, as with PTSD patients. The UNH researchers believe that understanding the fundamentals of how classical conditioning shape neural connections in the brain could speed up the development of treatments for these disorders in the future.

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University of New Hampshire

Breathing may change your mind about free will

Have you ever gone ahead and eaten that piece of chocolate, despite yourself?

Do you inadvertently make decisions because you are hungry or cold? In other words, does the brain's processing of internal bodily signals interfere with your ability to act freely?

This line of thinking is at the heart of research that questions our ability to act on thoughts of free will. We already know that inner body signals, like the heartbeat, affect our mental states, can be used to reduce the perception of pain and are of fundamental importance for bodily self-consciousness.

Thanks to a new discovery, it turns out that these inner body signals do indeed affect acts of volition.

Scientists at EPFL in Switzerland have shown that you are more likely to initiate a voluntary decision as you exhale. Published in today's issue of Nature Communications, these findings propose a new angle on an almost 60-year-old neuroscientific debate about free will and the involvement of the human brain.

"We show that voluntary action is indeed linked to your body's inner state, especially with breathing and expiration but not with some other bodily signals, such as the heartbeat," explains Olaf Blanke, EPFL's Foundation Bertarelli Chair in Cognitive Neuroprosthetics and senior author.

At the center of these results is the readiness potential (RP), a signal of brain activity observed in the human cortex that appears not only before voluntary muscle movement, but also before one becomes aware of the intention to move. The RP is the signature of voluntary action since it consistently appears in brain activity measurements right before acts of free will (like being aware that one wants to reach for the chocolate).

Interpretations of the RP have been debated for decades. Some interpret the RP to show that free will is an illusion, since the RP precedes the conscious experience of free will. It seems to show that the brain commits to a decision (chocolate) before we are even consciously aware of having made that decision. [See box The readiness potential and interpretations.]

More recently, it was suggested that the RP could be an artefact of measurement, potentially putting free will back into our command.

But if we take on the view that our conscious decisions arise from a cascade of firing neurons, then the origin of the RP may actually provide insight into the mechanisms that lead to voluntary action and free will. The way the brain's neurons work together to come to a decision is still poorly understood. [See hidden patterns of brain activity unveiled by higher dimensional algebraic topology.] Our conscious experience of free will, our ability to make decisions freely, may then be intricately wired to the rest of our body. [See box Acts of free will and inner states of the body]

The EPFL results suggest that the origin of the RP is linked to breathing, providing a new perspective on experiences of free will: the regular cycle of breathing is part of the mechanism that leads to conscious decision-making and acts of free will. Moreover, we are more likely to initiate voluntary movements as we exhale. (Did you reach for that piece of chocolate during an exhale?)

These findings suggest that the breathing pattern may be used to predict 'when' people begin voluntary action. Your breathing patterns could also be used to predict consumer behavior, like when you click on that button. Medical devices that use brain-computer interfaces could be tuned and improved according to breathing. The breathing-action coupling could be used in research and diagnostic tools for patients with deficits in voluntary action control, like obsessive compulsive disorders, Parkinson disease, and Tourette syndromes. Blanke and Hyeong-Dong Park, first author of this research, have filed a patent based on these findings.

Free will hijacked by interoceptive signals?

More generally, the EPFL findings suggest that acts of free will are affected by signals from other systems of the body. Succumbing to that urge to eat chocolate may depend more on your body's internal signals than you may realize!

Blanke elaborates, "That voluntary action, an internally or self-generated action, is coupled with an interoceptive signal, breathing, may be just one example of how acts of free will are hostage to a host of inner body states and the brain's processing of these internal signals. Interestingly, such signals have also been shown to be of relevance for self-consciousness."

You may be tempted to blame acts of chocolate binging on interoceptive electrical signals hijacking your free will. The gut-mind connection is an active field of research and interoceptive messages sent to the brain certainly impact food cravings. For now, this latest EPFL research only improves predictions of when you will indulge in that craving, and not what you actually crave.

Acts of free will and inner states of the body

The prevailing view in neuroscience is that consciousness is an emergent phenomenon of the brain. Firing of the brain's neurons leads to consciousness and the feeling of free will or voluntary action. By belonging to the physical universe, the brain's electrical activity within the constraints of anatomy, is subject to the laws of physics. In this sense, brain signals encoding the body, lungs and heart might naturally affect the brain's cognitive states too and therefore influence acts of free will.

To test whether the RP depends on the body's inner state and the brain's representation thereof, Blanke and colleagues asked 52 subjects to press a button at will at Campus Biotech in Geneva. EEGs monitored brain activity, a belt around the chest measured breathing activity and cardiac activity was recorded.

The scientists found that the RP and voluntary action (pressing the button) is linked to the body's inner state - the regular breathing cycle - but not to the heartbeat. Participants initiated voluntary movements more frequently during an exhale than an inhale and were completely unaware of this breathing-action coupling. The RP was also modulated depending on the breathing cycle.

EPFL scientist and first author of the study Hyeong-Dong Park explains, "The RP no longer corresponds only to cortical activity 'unconsciously preparing' voluntary action. The RP, at least partly, reflects respiration-related cortical processing that is coupled to voluntary action. More generally, it further suggests that higher-level motor control, such as voluntary action, is shaped or affected by the involuntary and cyclic motor act of our internal body organs, in particular the lungs. Still the precise neural activity that controls breathing remains to be mapped."

The readiness potential and interpretations

Philosophers, psychologists, and more recently neuroscientists have long debated our ability to act freely. The meaning of the readiness potential (RP) has been questioned ever since its discovery by neuroscientists Hans Helmut Kornhuber and Lüder Deecke in 1965, and later regarding its relation to free will in neuroscientist Benjamin Libet's experiments.

The entire brain consists of approximately 100 billion neurons, and each individual neuron transmits electrical signals as the brain works. Electrodes placed on the head can measure the collective electrical activity of the brain's neurons, seen as wavy lines called an electroencephalogram (EEG).

In 1965, neuroscientists Hans Helmut Kornhuber and Lüder Deecke conducted a seminal experiment to test voluntary action and discovered a recurring pattern of brain activity. They placed EEG electrodes on top of the subject's head, and asked the subject to press a button at will. Kornhuber and Deecke discovered that the EEG consistently exhibited a rising slope of wavy lines, the readiness potential, 1 second or more before voluntary movement.

In the early 1980s, neuroscientist Benjamin Libet further tested the relationship between the RP and conscious awareness or intention of voluntary action. His highly influential results showed that approximately 200ms before his subjects pressed the button, they were aware of an urge or the intention to act, something Libet referred to as the W time, and yet the RP consistently preceded W time.

Libet suggested that these findings showed that even before we make a conscious decision of voluntary action, the brain was already unconsciously activated and involved in planning the action.

Some have interpreted the relation between the RP and W time as an indication that human free will might be an illusion. The RP is viewed as the brain committing to a decision (to press the button) before the subject is even aware of having made that decision. If commitment to a decision is being made before we are even aware of it, then what mechanism is making the decision for us?

For the neuroscientist who considers consciousness to arise from brain activity (versus brain activity arising from consciousness), Libet's results may not surprising, since the conscious experience of free will is viewed as an emergent phenomenon of brain activity.

Yet, Libet's results are in conflict with the notion of free will and voluntary action in philosophy of the mind, in folk psychology, in culture, and in legal matters.

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Ecole Polytechnique Fédérale de Lausanne

An invasive flatworm from Argentina, Obama nungara, found across France and Europe

image: Obama nungara.

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Photo by Pierre Gros

One of the consequences of globalization is the inadvertent human-mediated spread of invasive species. The presence of a new invader, named Obama nungara, is reported in France by an international team led by Jean-Lou Justine of ISYEB (Muséum National d'Histoire Naturelle, Paris, France). This is the first study of this invasion, reported in an article published in the open-access journal PeerJ.

As is the case for other land planarians including the New Guinea flatworm, Platydemus manokwari, and giant hammerhead flatworms from Asia, already reported in France, the origin of the invasion by O. nungara is likely to be via the international trade of plants, since adult planarians and cocoons can easily travel in potted plants. However, in contrast to the previously recorded species of land planarians that have been found only in a limited part of the country, the flatworm Obama nungara is reported from an area representing three quarters of metropolitan France.

Land flatworms are predators of soil animals, including earthworms and molluscs, and thus are a possible threat to the biodiversity of native animals and to soil ecology, although the ecological impact has yet to be studied.

To date, the presence of Obama nungara has been occasionally recorded from several countries in Europe, including Spain, Portugal, UK, Italy, and Belgium. However, in none of these countries has a study of the extent of the occurrence of O. nungara been performed.

Observations in France, mainly based on citizen science, include 530 verified records received from 2013 to 2018. Results show that the species is now present in 72 of the 96 Departments of Metropolitan France, an area representing 75% of the country. The species is especially abundant in gardens along the Atlantic coast and the Mediterranean coast. The species has also been recorded on Corsica in the Mediterranean Sea. Most records were from a low altitude, and there are no records of the species from mountainous regions such as the Alps, Pyrenees and Massif Central. New records from Italy and Switzerland are also included in the study.

Molecular studies, based on the Cytochrome Oxidase Type 1 sequences, show that Obama nungara has three populations: two in Argentina and one in Brazil. Only one of these populations, "Argentina 1" in the paper, is present in Europe, including all France, and Spain, Portugal, UK, Italy, Belgium, and Switzerland. The population from Brazil has not reached Europe; Argentina is the sole source of this invasive species in Europe.

The extensive distribution of the species and its reported local abundance, combined with its predatory character, make Obama nungara a potential threat to the biodiversity and ecology of the soils in Europe. The authors estimate that O. nungara is the most threatening species of all invasive land planarians present in Europe.

In a climate of open science, the database of citizen science records and the molecular matrix are made public together with the paper. The authors mention that citizen science was extremely useful for evaluating the invasion, but urge to consider possible bias in the records, due to media coverage. Mention of land flatworms in the media immediately produced bursts of records, therefore hampering a correct analysis of the abundance of the species over time. It is expected that this new paper will encourage new records of Obama nungara from members of the public, not only in France but possibly other countries.

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PeerJ

All women should be educated after childbirth about high blood pressure

GRAPEVINE, Texas -- After childbirth, it is not uncommon for women to experience high blood pressure. If not treated, it can have serious consequences, including stroke and, in some cases, death. It is unclear what causes high blood pressure after childbirth, or who may develop it.

In a study to be presented today at the Society for Maternal-Fetal Medicine's (SMFM) annual meeting, The Pregnancy Meeting™, researchers will unveil findings that suggest all women, regardless of whether they have a history of high blood pressure, need to be educated about the signs and symptoms of high blood pressure, also known as postpartum hypertension.

The study looked at 164 women from September 2016 to July 2019 who gave birth at Children's Memorial Hermann Hospital in Houston and were readmitted with high blood pressure. The majority of women (64.6%) were readmitted within seven days, and 39 percent of those women were not diagnosed with high blood pressure prior to being discharged.

"Texas has one of the highest maternal mortality rates in the nation. As clinicians, we're always looking for ways to tailor interventions so we can reduce deaths," said the study's lead author Conisha Holloman, MD, a maternal-fetal medicine fellow with McGovern Medical School at UTHealth in Houston. "At our hospital, we noticed a lot of women were being readmitted after giving birth with high blood pressure, even when they didn't have a history of high blood pressure. While clearly more research needs to be done on what causes high blood pressure after childbirth, what our study reveals is a strong need to educate all women ? not just those who may be at a higher risk -- about the signs and symptoms of high blood pressure before they are discharged."

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Society for Maternal-Fetal Medicine

Oh my aching back: Do yoga, tai chi or qigong help?

image: People with chronic low back pain are at increased risk of functional limitations, job-related disability, and potential long-term disability. Moreover, the economic burden of chronic low back pain is high due to the cost of medications such as opioids, procedures, hospitalization, surgical treatment, and absence from work.

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Florida Atlantic University

It's a pain. About 80 percent of adults in the United States will experience lower back pain at some point. Treating back pain typically involves medication, including opioids, surgery, therapy and self-care options. Efforts to reduce opioid use and increase physically based therapies to reduce pain and increase physical function and safety are crucial.

Patients are often advised to use non-pharmacological treatments to manage lower back pain such as exercise and mind-body interventions. But, do they really help? In a review published in the journal Holistic Nursing Practice, researchers from Florida Atlantic University's College for Design and Social Inquiry and Christine E. Lynn College of Nursing evaluated the evidence of effects of three movement-based mind-body interventions on chronic low back pain. They examined yoga, tai chi, which combines gentle physical exercise and stretching with mindfulness, and qigong, a traditional Chinese meditative movement therapy focused on body awareness and attention during slow, relaxed, and fluid repetitive body movements. Little is known about the effects of movement-based mind-body intervention, in particular qigong and tai chi.

Researchers compared and contrasted yoga, tai chi and qigong by examining frequency and duration of these interventions; primary and secondary outcomes; attrition rates and possible adverse events; and results. Findings from their review provide empirical evidence regarding the benefits of yoga, tai chi, and qigong, which have been recommended by health care providers for patients with lower back pain.

"Back pain is a major public health issue often contributing to emotional distress such as depression and anxiety, as well as sleep issues and even social isolation," said Juyoung Park, Ph.D., corresponding author and an associate professor in the Phyllis and Harvey Sandler School of Social Work within FAU's College for Design and Social Inquiry. "We reviewed data to determine the effects of movement-based mind-body interventions on chronic back pain, psychological factors, coping strategies, and quality of life in people suffering with back pain. Our goal was to provide a comprehensive assessment of the effects of these interventions to be able to offer information across disciplines to implement evidence-based interventions to reduce such pain."

Of the 625 peer-reviewed articles the researchers identified, 32 met inclusion criteria and were included in the review. Results found that the majority of these articles showed movement-based mind-body interventions to be effective for treatment of low back pain, reporting positive outcomes such as reduction in pain or psychological distress such as depression and anxiety, reduction in pain-related disability, and improved functional ability. Among the key findings, researchers discovered that longer duration and high-dose yoga intervention showed reductions in back pain while tai chi reduced acute lower back pain in males in their 20s. Tai chi also was more effective than stretching for lower back pain in young males. In the general community, tai chi showed greater reductions in pain intensity, bothersomeness of pain symptoms, and pain-related disability than the control intervention. Because there are only three qigong studies to date, it was unclear to the researchers whether this intervention is useful in treating chronic lower back pain. Existing research suggests positive benefits of yoga, however, tai chi and qigong for lower back pain are still under-investigated.

"Two of the studies we examined in our review were focused on the effects of movement modality, specifically yoga, in veterans. Many military veterans and active duty military personnel experience chronic low back pain and are affected by this pain more than the general population," said Cheryl Krause-Parello, Ph.D., co-author, a professor and director of Canines Providing Assistance to Wounded Warriors (C-P.A.W.W.) within FAU's Christine E. Lynn College of Nursing, and a faculty fellow of FAU's Institute for Human Health and Disease Intervention (I-HEALTH). "Our review provides emerging evidence that movement-based mind-body interventions could benefit veterans and others experiencing chronic low back pain."

The review included both randomized and nonrandomized studies with a total of 3,484 subjects ages 33 to 73 years old. Study sample sizes ranged from 25 to 320 subjects. The majority of articles reported on yoga (25), followed by tai chi (four), and qigong (three). Most of the yoga studies were conducted in India, followed by the U.S., while other studies were conducted in Australia (tai chi) and Germany (qigong).

People with chronic low back pain are at increased risk of functional limitations, job-related disability, and potential long-term disability. Moreover, the economic burden of chronic low back pain is high due to the cost of medications such as opioids, procedures, hospitalization, surgical treatment, and absence from work.

"Yoga, tai chi and qigong could be used as effective treatment alternatives to pain medications, surgery, or injection-based treatments such as nerve blocks, which are associated with high incidence of adverse effects in treating lower back pain," said Park. "We need more clinical trials and empirical evidence so that clinicians can prescribe these types of interventions with more confidence for managing lower back pain in their patients."

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Florida Atlantic University

A new approach to calm that angry nose

image: Serum soluble SEMA4D levels were elevated in patients with ECRS and positively correlated with disease severity. Cell surface expression of SEMA4D on eosinophils from ECRS patients was reduced, which was due to MMP-9-mediated cleavage of membrane SEMA4D. Soluble SEMA4D induced eosinophil transendothelial migration. Treatment with anti-SEMA4D antibody ameliorated eosinophilic infiltration in sinus tissues.

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Osaka University

Osaka, Japan - Eosinophilic chronic rhinosinusitis (ECRS) is a type of airway disease involving nasal inflammation. Many studies have attempted to understand the molecular-based pathogenesis of recurrent ECRS; none have provided a clear explanation, until now.

In a new study published in The Journal of Allergy and Clinical Immunology, a team led by researchers from Osaka University investigated the activity of semaphorin protein, a cell-surface molecule that participates in nervous system signaling and immune responses. They found that semaphorin protein contributes to allergic reactions and development of nasal polyps in patients with ECRS.

In ECRS, inflammation leads to development of nasal polyps containing eosinophils (a subset of white blood cells). Treatment options include sinus surgery and systemic glucocorticoids. However, the effectiveness of these treatments can be insufficient and multiple side effects can occur. Thus, targeted molecular therapies may provide novel treatment options for patients with ECRS without these drawbacks. Because semaphorin has been identified in inflamed airway tissues, it is an attractive candidate for use in such therapies.

"In this study, we found that serum levels of semaphorin proteins were elevated in patients with ECRS, and that these levels were positively associated with multiple measures of disease severity," says Masayuki Nishide, corresponding author on the study. "We suspected that semaphorin protein played an important role in the pathogenesis of ECRS."

The Osaka University team found that activated eosinophils expressed high levels of semaphorin protein on the cell surface, which could be released into the surrounding environment through an enzymatic reaction. This soluble form of semaphorin protein could enable eosinophils to pass through endothelial cell lining, resulting in the onset of inflammation and formation of nasal polyps.

"Our analyses revealed that, in a mouse model of ECRS, mice without semaphorin protein had less nasal inflammation than normal mice, so we tested whether blocking semaphorin with an antibody could affect inflammation in normal mice with ECRS," says Takeshi Tsuda, lead author on the study. "As expected, we found that treatment with an anti-semaphorin antibody substantially reduced nasal inflammation in mice with ECRS."

Based on the results in the mouse model, the Osaka team concluded that anti-semaphorin antibody could provide a new treatment option for patients with ECRS. Additionally, the increased levels of semaphorin protein in patients with ECRS suggest that semaphorin protein can be used as a biomarker for ECRS in patients with nasal inflammation.

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Osaka University

The unchanging viscosity of cells

image: Viscosity is closely guarded within the cell, though at present we don't know who the guardians are.

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IPC PAS, Grzegorz Krzyzewski

The only thing that appears to be unchanging in living cells is that they are constantly changing. However, scientists from the IPC PAS have managed to show that there is a certain parameter that does not change. It's their viscosity. This research, although basic, may contribute to the development of completely new diagnostic and therapeutic methods.

It would seem that during the life of cells - DNA replication, protein formation, the constant changes in their quantity, metabolites, etc., such drastic transformations take place within them that the viscosity related to the ratio of water to the number of biological molecules in the cell should, (when looked at intuitively), change. This is what many scientists thought, including the authors of the paper published in Scientific Reports. "We wanted to examine how the viscosity of cytoplasm changes at various important moments in a cell's life, such as during division. That's why the result, i.e. the constancy of viscosity, was a complete surprise to us," says Dr Karina Kwapiszewska.

The measurement itself was a difficult and tedious process. A full cell cycle takes about 24 hours, and although cells can be synchronized like dancers in a ballet, i.e. made to all divide roughly at the same time, they cannot be persuaded to wait for an observer to take a picture of them. They constantly dance to their own inner music.

"Here a big nod to my colleague, Dr. Krzysztof Szczepa?ski, who spent more than one night carrying out fluorescence correlation spectroscopy measurements. They have to be performed every half hour during the whole cell cycle, and the cell won't wait until the morning to divide," says Dr Kwapiszewska. "Thanks to him and his perseverance we mapped the viscosity throughout the entire cycle. And that's with the right number of repetitions. This is the only way we could prove that what we measured was an actual parameter, not an artefact," she adds.

What's more, the IPC PAS scientists discovered that the cell's viscosity remains constant regardless of whether the cell comes from the lung or e.g. the liver, although these are very different tissues. And since it is constant, this means that the cell must need it to be so for a purpose. Especially since the size of cells can vary within a single population (e.g. skin cells) even ten-fold and this does not matter to them as much as their viscosity. So there must be a mechanism that regulates it.

The viscosity of a medium is undoubtedly very important for biochemical processes. Simply put, the higher the viscosity, the harder it is for particles to meet in order to react. Cells must actively regulate their viscosity otherwise reactions would be slower in some conditions and faster in others. And if one of the reactions were to slow down too much - the whole system could fall apart and the cell would never be able to restore its balance. "In one of our team's earlier papers (Soza?ski et. al., Phys Rev Lett 2015) it was shown that only a 6-fold increase in viscosity (this really isn't much) is sufficient to stop the entire active transport in a cell," explains Dr Kwapiszewska.

And here we come to the potential, though at present distant, applications of this discovery. Since an increase in viscosity inhibits life processes in the cell then perhaps this can be used, for example, to create therapeutics against cancer cells. The sort that would employ physical processes instead of, for example, inhibiting DNA replication.

"We also suspect that some neurodegenerative diseases may be caused by a local increase in viscosity in cells," says the author. "So, compensating for this could be a way to stop damage in Parkinson's or Alzheimer's disease and improve a patient's prognosis."

Now researchers want to find out how viscosity changes during cell death and whether this change in viscosity is the result or the cause of the process itself.

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Institute of Physical Chemistry of the Polish Academy of Sciences

Global study maps cancer mutations in large catalogue

Mutations in 38 different types of cancer have been mapped by means of whole genome analysis by an international team of researchers from, amongst others, the University of Copenhagen, Aarhus University, Aarhus University Hospital, and Rigshospitalet. The researchers have compiled a catalogue of the cancer mutations that will be available worldwide to doctors and researchers.

Globally, cancer is one of the biggest killers and in 2018, an estimated 9.6 million people died of the disease. In order to provide the best treatment for the disease, it is essential to find out which mutations are driving the cancer.

In a major international collaboration called Pan-Cancer Analysis of Whole Genomes (PCAWG), researchers from the University of Copenhagen, Aarhus University, Aarhus University Hospital and Rigshospitalet have helped to map mutations in 38 different types of cancer.

The mutations have all been combined into a sort of catalogue. The catalogue, which is already available online, allows doctors and researchers from all over the world to look things up, consult with and find information about the cancer of a given patient.

'Most previous major studies have focused on the protein coding two percent of the genome. We have studied and analysed the whole genome, and our analyses of mutations that are affecting cancer genes have enabled us to genetically explain 95 percent of the cancer occurrences we have studied by means of mutations,' says co-author Joachim Weischenfeldt, Associate Professor at the Biotech Research & Innovation Centre, University of Copenhagen, and the Finsen Laboratory, Rigshospitalet.

'So, if you know which mutations have caused cancer, the so-called driver mutations, you will be able to better tailor a treatment with the most suitable drugs or design new drugs against the cancer. Precision medicine is completely dependent on the mapping of driver mutations in each cancer, in relation to diagnosis, prognosis and improved treatment,' says co-author Jakob Skou Pedersen, professor at Bioinformatics Research Centre and Department of Clinical Medicine, Aarhus University, and Aarhus University Hospital.

The new research results are published in a special edition of the scientific journal Nature with focus on PCAWG. To date, it is the largest whole genome study of primary cancer. This means that the analysis was performed based on material from the tissue in which the tumour originated and before the patient has received any treatment.

From a Handful to 100,000 Mutations

The researchers have mainly analysed and had data on the most common types of cancer such as liver, breast, pancreas and prostate cancer. In total, they have analysed whole genome-sequenced tumour samples from more than 2,600 patients.

Based on their analyses, they could see that the number of mutations in a cancer type varies a lot. Myeloid dysplasia and cancer in children have very few mutations, while there may be up to 100,000 mutations in lung cancer.

But even though the number of mutations spans widely, researchers could see that on average there were always 4-5 mutations that were driving the disease, the so-called drivers - no matter what type of cancer it was.

'It is quite surprising that almost all of them have the same number of driver mutations. However, it is consistent with theories that a cancerous tumour needs to change a certain number of mechanisms in the cell before things start to go wrong,' says Jakob Skou Pedersen.

In the catalogue, the researchers have divided the mutations into drivers and passengers. Driver mutations provide a growth benefit for the cancer, while passenger mutations cover all the others and are harmless. The vast majority of all mutations are passengers.

Genetics or Tissue

To store and process the vast amount of data, the research team has used so-called cloud computing, using 13 data centres spread across three continents. They have had centres in Europe, the US, and Asia.

The large data set has been necessary to establish what was common and unique to the different types of cancer. Today, cancer is divided according to the tissue in which the disease originates, for example breast, brain, and prostate.

The researchers found many things that were completely unique to each type of tissue. Conversely, they also found many common traits across the tissue types. According to Joachim Weischenfeldt, there is thus a need to rethink the way we think about cancer.

'Cancer is a genetic disease, and the type of mutations is often more important than where the cancer originates in the body. This means that we need to think of cancer not just as a tissue-specific disease, but rather look at it based on genetics and the mutations it has.'

'For example, we may have a type of breast cancer and prostate cancer where the driver mutations are similar. This means that the patient with prostate cancer may benefit from the same treatment as the one you would give the breast cancer patient, because the two types share an important driver mutation,' says Joachim Weischenfeldt.

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University of Copenhagen - The Faculty of Health and Medical Sciences

Growing new blood vessels could provide new treatment for recovering movement

Many health conditions - ranging from disease of particular organs such as heart and lungs, widespread metabolic issues such as diabetes, or following trauma such as spinal cord injury - cause difficulties with movement. This can severely affect quality of life and new research published today in the Journal of Physiology highlights the link between loss of the smallest blood vessels in muscle and difficulties moving and exercising. Understanding this link opens up the possibility of aiding recovery by growing more blood vessels in your muscles.

When we are physically active, our heart and lungs increase the amount of oxygen in our blood that is delivered to our working muscles. Our capillaries, the smallest blood vessels, are the gateway between fuel supplied by the circulating blood and the demand generated within muscle cells. Therefore, in order for your muscles function properly, the capillaries need to be in good shape. Unfortunately, the consequence of many heath conditions is that the muscle loses capillaries and therefore movement becomes difficult.

Heavy smokers can suffer from 'smoker's leg', which is where arteries narrow and become blocked. An existing treatment for this is to widen blood vessels to improve circulation. However, this new research shows that more blood flow might not be the solution, and instead increasing the number of small blood vessels, i.e. capillaries, might be more helpful for recovering movement.

The researchers used a rat model of heart disease to study the effect of restricting the number of working capillaries in muscle on movement. Using an animal model was key because in humans you wouldn't be able to look at a change in just one consequence of the disease, as there are usually a number of problems evident at the same time.

Stuart Egginton from the University of Leeds, senior author on the study, said:

"By studying muscle we have isolated one of the complications found in many serious diseases, and found that increasing the number of small blood vessels is a new treatment option alongside the more traditional approach of widening large vessels. This research could help treat people suffering from difficulty moving, which is one of the most debilitating effects of heart disease or diabetes."

Credit: 
The Physiological Society

Direct synthesis of azulene continues to reveal alluring properties

image: The blue color is hard to observe in its crystal form. Azulene emits an odor resembling mothballs.

Image: 
Shinshu University

Azulene is a pretty neat substance. As the name suggests, it displays a peculiar blue color. First synthesized in the 1930s, azulene has been used in medicine for its bioactive properties. Now azulene derivatives are being studied for use in organic electronics such as n-type semiconductors, solar cells and non-linear optics. This is made possible by the functionalization of the azulene ring. Odd-positions of the ring had been researched extensively for their high reactivity, though it was hard to select their functionality due to their electronic properties. Highly functionalized azulenes were enabled by cross-coupling reactions of even-numbered positions of azulenes. However, it has been difficult to synthesize these precursors.

Associate Professor Taku Shoji at Shinshu University et al. was successful in direct synthesis of 2-arylazulene. One of the few researchers who specialize in azulene synthesis, Professor Shoji states that the breakthrough in this study allows for the synthesis of azulene on a gram-scale instead of milligrams. The previous possible production volume made it difficult for possible use in organic electronics. Being able to synthesize azulenes from readily available 2H-cyclohepta[b]furan-2-one derivatives and silyl enol ether is a great step forward in practical applications.

The fluorescence of the azulene derivatives in acidic conditions (which can be seen in the photo) was observed unexpectedly during this study. Though this property of azulene derivatives had been previously reported, the research group found that 2-phenylazulenes exhibit the emission in acidic media and the fluorescence wavelength depends on the electronic properties of the substituents on the substituted benzene ring. The group is collaborating with photochemical experts to elucidate the mechanism of this unexpected fluorescence.

Professor Shoji and his team continue to attempt to synthesize 2-arylazulene at a lower temperature using an appropriate catalyst. Professor Shoji states that "although azulene have been studied for a hundred years, new synthetic methods, reactivity and physical properties continue to be discovered." He remains fascinated by what this mysterious blue substance can reveal and ultimately be applied for.

Credit: 
Shinshu University

End-of life-care needs will nearly double over the next 30 years, highlighting urgent need for funding

New research at Trinity College Dublin, published today (Thursday, February 6th, 2020), shows that the number of people dying in Ireland with palliative care needs will increase 84% to 2046.

The study, conducted at Trinity's Centre for Health Policy and Management and The Irish Longitudinal study on Ageing (TILDA), estimated how many people will die from a serious disease such as cancer, heart disease, organ failure and dementia to 2046. The estimated 84% increase compares to 43% for England and Wales in a similar period.

Projected increases are underpinned by two factors of population ageing: increasing absolute numbers of people dying, and increasing proportion of people who experience a serious illness prior to death. Increases are most observable in the 85+ age group, which is growing rapidly. The difference with England primarily reflects Ireland's population, which is now younger than the EU average and so will have faster-growing needs in the 21st century.

Palliative care is a type of specialist supportive care that aims to improve quality of life for people living and dying with serious illness. It is provided in Ireland in hospitals, by homecare teams and at inpatient hospices.

Professor Karen Ryan, Consultant in Palliative Medicine at the Mater and St Francis Hospice, and Clinical Professor in the School of Medicine at UCD, said that the results indicate an urgent need to address funding and workforce in palliative care:

"Ireland is recognised to have a high standard of palliative care provision. Our data show that capacity must increase significantly if we are to maintain that.

People are living longer with more serious illnesses. This is a success story for society but also brings challenges.

Sláintecare priorities include a revised national palliative care policy in 2020 and we hope that our results will inform this review, so that people dying with serious illness and their families receive the care and support they need during this unique life event."

The study also estimated numbers of people who will live with serious illnesses requiring expert support in the years prior to death. They found that the number of people living with a serious disease outnumber those in the last year of life with a serious disease by about 12:1.

Dr Peter May, Research Assistant Professor in Health Economics at Trinity and lead author of the study, said that this has important implications also:

"Population ageing means not only more people dying with serious medical conditions but many more people living with them also.

The highest average illness burden and health care need is of course among those near the end of life. But total population needs will be driven by all people experiencing these conditions.

"Health care provision has to change to reflect those needs. We need better anticipatory and supportive care to lower avoidable hospital admissions and keep people living at home and in their communities for as long possible."

Credit: 
Trinity College Dublin

Sugar ants' preference for pee may reduce greenhouse gas emissions

image: Sugar ants mining urine in sand on Kangaroo Island

Image: 
UniSA / Sophie Petit

An unlikely penchant for pee is putting a common sugar ant on the map, as new research from the University of South Australia shows their taste for urine could play a role in reducing greenhouse gases.

Led by wildlife ecologist Associate Professor Topa Petit, the Kangaroo Island-based research found that sugar ants prefer urine over sugar - the food source after which they're named - nocturnally foraging on it to extract nitrogen molecules, some of which could end up in the greenhouse gas, nitrous oxide.

The Australian-first study compared the behaviours of sugar ants (Camponotus terebrans) as they were exposed to different concentrations of urine (human and kangaroo ~ 2.5 per cent urea), sugar water (20 per cent and 40 per cent), and urea in water (at 2.5 per cent; 3.5 per cent; 7 per cent and 10 per cent), finding that sugar ants were most attracted to higher concentrations of urea, mining them for long periods within a dry sand substrate.

While other ants are known to be attracted to urine, this is the first time that ants have been observed mining dry urine from sand, and for a long period of time.

Assoc Prof Petit says the curious discovery could play a role in nitrogen cycling.

"When I first noticed the ants swarming to scavenge urine, it was purely by accident. But under research conditions we found that the ants determinedly mined urea patches night after night with greater numbers of ants drawn to higher urea concentrations," Assoc Prof Petit says.

"Camponotus terebrans are undoubtedly looking for urea in urine because, similar to certain other ant species, a bacterium in their digestive tract allows them to process urea to get nitrogen for protein.

"This remarkable ability to extract urea from dry sand not only shows how sugar ants can survive in arid conditions, but also, how they might reduce the release of ammonia from urine, which leads to the production of nitrous oxide, a highly active greenhouse gas."

Nitrous oxide (NO2) is a greenhouse gas 300 times more potent than carbon dioxide. And while less abundant than carbon dioxide emissions, its presence in the atmosphere has increased substantially over the past decade, accelerated mostly by the widespread use of fertilisers.

Assoc Prof Petit says that while there is still a lot to learn about the foraging behaviours of sugar ants, the study shows a symbiotic relationship between ants and vertebrates such as kangaroos in dry environments, and evidence of the nitrogen cycle at work.

"The ability of sugar ants to thrive in dry, sandy environments and use sources of nitrogen that may not be available to other species is impressive. It may give them a competitive advantage by allowing them to feed more offspring and therefore increase their numbers," Assoc Prof Petit says.

"Researchers working on ants as bio-indicators on grazed and ungrazed lands should take ants' ability to process urea into account, because large amounts of urine will probably affect the assortment of ant species in the area. It would also be interesting to investigate how much ants may modify the urine ammonia volatilises from paddocks.

"This is not the last we will hear about these sugar ants - they could open up a whole new field of research."

Credit: 
University of South Australia

A new learning model to enhance citizen participation

How to teach citizens to become active members of the society? Peter Ehrström, Head of Research in Regional Science, and Marina Lindell, Project Researcher at the Social Science Research Institute of Åbo Akademi University in Vaasa, Finland, approached the question by inviting a group of students on a course that utilized a method called Deliberative Walks. The experiment produced very positive results.

Deliberative Walks, developed by Ehrström and Harri Raisio, University Lecturer at the University of Vaasa, is a model of participatory democracy that combines citizens' juries and development walks.

The method is intended to be applied in matters concerning, for example, urban planning. It can help to find out the views of various groups of people on how a particular area should be developed.

"Some of the models of participatory democracy are too theoretical. In case a method aims primarily at collecting expert views, there is a risk that people with lower levels of education, for instance, feel that they are at a disadvantage. That would be unfortunate, as the specific purpose of participatory democracy is to listen to all opinions, not just those of the elite", explains Ehrström.

The participants of the course included both international and local students of various subjects, women as well as men. They were assigned to deliberate on the planning of an area around the Åbo Akademi University campus in Vaasa and create new development ideas for the area.

"The idea is to bring together people from various backgrounds and with different skills and to get them to discuss, deliberate, compromise and make decisions. As a result of all this, they should be able, as a group, to present and justify the conclusion they have reached together. It is especially valuable to offer international and local students a chance to meet, work together and establish relationships across subject, language and cultural borders. The ability to be open and receptive to new impressions, ideas and opportunities for cooperation is particularly important in today's world", says Ehrström.

The course also had an educational aspect: In order to strengthen the participants' learning processes, it combined different teaching methods, both place-based and theoretical ones.

The course started with a series of lectures on, for example, participatory democracy, urban planning, architecture and art. After that, the participants took a two-hour development walk in and around the Academill building as well as in the museum area of the inner harbour of Vaasa. During the walk, the participants had the opportunity to see and experience the area and meet people who work there to learn about their points of view.

To wrap up the course, the participants spent a whole day discussing ideas on how to develop the area. Many proposals were made but in the end the deliberation process led to a concrete outcome with five practical proposals that all participants agreed upon. These proposals were presented to local decision-makers and representatives of the media.

According to feedback from questionnaires and interviews, the course increased the participants' engagement in the society as well as their understanding of participatory democracy as a part of political decision-making.

"We should keep in mind that we need more than just active citizens. Many of our students will become decision-makers in the future, and it is important for them to understand that tools like this are available for decision-makers to engage citizens", says Ehrström.

The course experience also enhanced the participants' sense of inclusion and boosted their self-confidence to express and discuss their own opinions.

"By adding elements like place-based learning and outdoor pedagogy and by including varied discussion formats, we make discussions more inclusive and more appealing to people who normally might not take part in them at all. Decision-makers and citizens move closer towards each other and learning becomes more equal", says Marina Lindell.

"Above all, the method aims at making all participants feel that their opinions are valuable. Some contribute by bringing in theoretical expertise while others provide local knowledge, and all of them should feel that their contribution is important", Ehrström points out.

Ehrström arranged a course like this in Hamburg, Germany, in 2019. As both experiments have been very successful, similar courses will be offered within the subject Regional Science at Åbo Akademi University in Vaasa during the academic years 2020-2022.

"Universities can play a central and important role in societal development when it comes to teaching citizens to become active members of the society. Universities could also take a more active role in facilitating discussion on political issues of long-term importance. By creating methods and models to be applied in the development of the society and citizen participation, we can strengthen the civic society on various levels. To be able to develop as democratic citizens, we need to learn to debate and discuss", says Lindell.

Credit: 
Abo Akademi University

Researchers refute fifty-year old doctrine on cell membrane regulation

image: This is Robert Ernst, Professor of Molecular Biology at Saarland University.

Image: 
Saarland University/Thorsten Mohr

The boundary between life and non-life is a remarkably narrow one. A central hallmark of life is the cellular membrane - a protective barrier of only a few nanometers thickness (one nanometre is a millionth of a millimetre) that is composed of proteins and two fluid layers of water-insoluble lipids. The function and integrity of this lipid bilayer is essential for the survival of the cell. If the cell membrane (or plasma membrane as it is also known) is compromised, the cell will die.

'But this boundary is more than just a semi-permeable, passive barrier' explains Robert Ernst, Professor of Molecular Biology at Saarland University, whose research focuses on improving our understanding of these ultra-thin, flexible barriers around our cells. 'Cell membranes are astonishing materials with bizarre properties that are difficult to imagine. They are extremely soft, yet they can cope with pressures that are hundreds of times greater than atmospheric pressure. At the same time, they have liquid-like properties and the ability to self-repair. This unique material protects the our cells from physical and chemical stress, facilitates communication between cells, mediates uptake of nutrients, and it wards off invading pathogens,' says Ernst.

For a system that has to perform such a variety of functions, it is critical to have fine-tuned properties to warrant full functionality. 'The cell membrane is a self-regulated system that is able to optimize its composition to each environmental condition.' To illustrate this adaptability, Robert Ernst chooses the image of a reindeer with its hooves in the Arctic permafrost, while its head has a stable temperature of 37 degrees Celsius. 'The cell membranes close to the hoove are composed of an entirely different set of lipids than the membranes in the brain.' says Ernst.

For about the last fifty years, scientists have assumed that the fluid character of the membrane is crucial for this adaptivity. By sensing membrane fluidity, a cell would 'know' what to do to survive in the cold. When the membrane becomes more viscous or even freezes as the temperature falls, the cell reacts by producing a different set of lipids that does not freeze as easily. A perfectly logical and credible explanation, which found its way as the theory of 'homeoviscous adaptation' into the textbooks of biochemistry.

'Unfortunately, this is not what's happening,' says Robert Ernst.

Through a collaborative scientific study involving lead author Stephanie Ballweg, Robert Ernst's research team at the Saarland University and colleagues from Great Britain, Germany and the USA, the researchers have been able to refute the central assumption underlying the hypothesis of 'homeoviscous adaptation'. 'We have isolated the membrane sensor Mga2 from baker's yeast and investigated how it responds to membrane fluidity,' explains Ernst. 'According to the prevailing hypothesis, this sensor would trigger a response whenever the membrane viscosity increases. But that is not what we observe.' It turns out that the fluidity is irrelevant, but that the packing density of lipid atoms in a special region of the membrane determines whether or not the sensor is activated. 'This makes it possible for the sensor to distinguish between saturated and unsaturated fatty acids in the membrane lipids,' says Ernst, describing the findings that have swept away a fifty-year-old theory.

And why didn't someone come up with this idea earlier? 'Up until recently, the disciplines interested in membranes have worked somewhat in isolation with relatively little exchange,' says Ernst. 'In order to conduct this research project, it was crucial to bring together experts in physics, materials science, biochemistry, and genetics.' Only by the synergy released by this interdisciplinary team it was possible to test the validity of the prevailing model. Based on these findings, bioscientists around the world can revisit the important question how membrane regulate the function of membrane proteins and how the lipid composition affects the communication between cells from a new perspective.

Credit: 
Saarland University